Portable marking tool

ABSTRACT

The improved portable marking tool has a head member with an axial bore therethrough. An anvil extends through the bore and has an outer end portion with marking devices thereon. An actuator member connected to a source of fluid under pressure is positioned in spaced relation to the head member and has a fluid actuated piston rod assembly movable longitudinally therein. A tubular connecting member is secured at one end to the head member and at the other end to the actuator member. Positioned within the tubular connector member is a striking tool that includes a longitudinally movable body portion coaxially positioned on a tubular support member. As the head member is depressed against an object to be marked, the rearward movement of the head member operably opens a spool valve to provide flow of fluid under pressure through a second conduit to the actuator member for actuation of the marking tool. Unless the marking devices are positioned in the axial bore of the head member and in abutting relation with the anvil member, the head member is restrained from moving and thereby opening the spool valve for actuation of the marking tool.

United States Patent Speicher Apr. 9, 1974 PORTABLE MARKING TOOL [75] Inventor: Edwin W. Speicher, Pittsburgh,-Pa.

[73] Assignee: M. E. Cunningham Company, lngomar, Pa.

22 Filed: Dec. 26, 1972 21 Appl. No.: 318,581

Related US. Application Data [63] Continuation-impart of Ser. No. 217,823, Jan. 14,

[52] Cl. 173/15, 173/119 [51] Int. Cl B25d 9/00 [58] Field of Search 173/119, 120, 15; 175/299, 175/300; 124/13 A, 11 A; 91/419; 227/7, 8

Primary ExaminerErnest R. Purser Assistant Examiner-William F. Pate, I11 Attorney, Agent, or FirmStanley J. Price, Jr. et a1.

[5 7] ABSTRACT The improved portable marking tool has a head member with an axial bore therethrough. An anvil extends through the bore and has an outer end portion with marking devices thereon. An actuator member connected toa source of fluid under pressure is positioned in spaced relation to the head member and has a fluid actuated piston rod assembly movable longitudinally therein. A tubular connectingv member is secured at one end to the head member and at the other end to the actuator member. Positioned within the tubular connector member is a striking tool that includes a longitudinally movable body portion coaxially positioned on a tubular support member. As the head member is depressed against an object to be marked, the rearward movement of the head member operably opens a spool valve to provide flow of fluid under pressure through a second conduit to the actuator member for actuation of the marking tool. Unless the marking devices are positioned in the axial bore of the head member and in abutting relation with the anvil member, the head member is restrained from moving the marking tool.

4 Claims, 10 Drawing Figures PAIENIEUAPR 91914 I 3 '802 516 saw a or 2 1 W I law.

PORTABLE MARKING TOOL CROSS REFERENCES TO RELATED APPLICATION BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an improved portable marking tool and more particularly to a spring propelled marking tool.

2. Description of the Prior Art U.S. Pat. No. 2,455,270, entitled Automatic Striking Tool, describes a spring actuated marking tool in which the striking spring is compressed behind the hammer while the hammer is retained in a locked position by balls within a ball cage portion of a support member. The anvil or punch is fixed within the support member. An annular ring member is positioned be tween a tubular support member and a tubular outer body. To impress a mark on the surface of an'object,

the striking tool is positioned with the end of the anvil or punch in abutting relation with the surface of the object to be marked. A force is applied to the end of the outer body portion that is resisted by the mass of the object to be marked. The force applied to the body moves the body portion toward the object to be marked and compresses the striking spring within the tubular body portion. The body portion after the spring is compressed a preselected amount moves the annular ring member toward the object to be marked relative to the fixed support member and moves the annular recessed portion in underlying relation with the ball cage of the support member to permit radial displacement of the balls to release the hammer. The hammer under the compressive force of the striking spring moves within the support member and strikes theend of the anvil or punch. The striking force is transferred through the anvil and marks the object.

With the automatic striking tool disclosed in U.S. Pat. No. 2,455,270 the object to be marked must be either unmovably positioned on a platform or have sufficient mass to remain stationary while the compressive force is applied to the striking spring. This requires either specially designed supports for the object to be marked or objects of sufficient mass to resist movement by the force required to compress the striking spring. There is a need for an improved portable marking tool that is capable of marking objects without rigidly positioning the object to be marked on fixed supports and also capable of marking relatively light objects.

SUMMARY OF THE INVENTION The hereinafter described invention is directed to an improved portable marking tool that has a head member with an anvil member movably positioned therein. A hammer member is arranged to move toward and away from the anvil member and to strike the anvil member with a marking force. Locking means are provided to lock the hammer member in spaced relation to the anvil member. A propelling means is provided to propel the hammer from the locked rearwardly spaced position toward the anvil member. A release means is also provided to release the locking means. An actuator is positioned in spaced relation to the head member with the hammer member therebetween. The actuator member is arranged to energize the propelling means. A connector member is connected at one end to the head member and at the other end to the actuator member so that the anvil member in the head member is operable to transfer the striking force from the hammer member to a surface of the object to be marked without exerting a substantial force by the marking tool against the object to be marked.

With the above improved portable marking tool it is now possible to lightly position or rest the marking end of the anvil in abutting relation with the object to be marked and propel the hammer by the actuator within the portable marking tool to impart a striking force to the anvil and mark the surface of the object.

Accordingly, the principal object of this invention is to provide an improved portable marking tool that does not require an immovable support for the object to be marked.

Another object of this invention is to provide an im' proved portable marking tool that will impress a mark in a relatively light object.

A further object of this invention is to provide, an improved portable marking tool that is actuated to impress a mark on 'an object upon contact of the marking tool against the surface of the object to. be marked.

Moreover an additional safety feature of the improved portable marking tool protects against ejection of the anvil member out of the marking tool by cutting off the supply of fluid to the actuator member when the marking devices are not positioned for operation within the head member and in abutting relation with the anvil member.

These and other objects of this invention will be more completely disclosed and described in the following specification, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in side elevation and section of my improved portable marking tool, illustrating the hamble marking tool, illustrating the spool valve arrangement for supplying fluid under pressure required to actuate the portable marking tool.

FIG. 6 is a view in end section taken along the line VI--VI of FIG. 5, illustrating the plurality of pressure pins extending forwardly of the cap member.

FIG. 7 is a view in section taken along the line VII- VII of FIG. 6 illustrating one of the plurality of pressure pins supported by a spring in the cap member..

FIG. 8 is a view similar to FIG. 5, illustrating the head portion in position to permit flow of fluid through the spool valve.

FIG. 9 is another view similar to FIG. 5, illustrating the head portion in locked position to prevent the flow of fluid through the spool valve.

FIG. 10 is a fragmented sectional view of the spool valve for supplying fluid to the actuator member according to my invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings and particularly FIGS. 1 and 2 there is illustrated my improved portable marking tool generally designated by the numeral 10. The marking tool 10 includes a head portion generally designated by the numeral 12 and an actuator generally designated by the numeral 14 positioned in spaced relation to each other and connected to each other by means of a tubular connecting member 16. A striking tool generally designated by the numeral 18 is positioned within the tubular connecting member 16 and is arranged to provide the striking force for the anvil 20.

Referring in greater detail to the components, the head member 12 has an axial bore 22 therethrough with a first enlarged threaded portion 24, a second enlarged threaded end portion 26 and an end shoulder 28 therebetween. The head portion 12 has a transverse slotted portion 30 that intersects the bore 22 and is arranged to house a chase 34. Within the chase 34'there are a plurality of marker elements 36 secured therein by means of a transverse pin 38. The anvil 20 has an enlarged rectangular head portion 40 arranged to abut the marker elements 36 and apply a striking force thereto as later explained.

The tubular connecting member 16 has a threaded end portion that is secured in the threaded bore.26 of head member 12 to rigidly secure the head member 12 to the tubular connecting member 16.

The actuator 14 has a cup shaped cylinder end portion 42 with a threaded opening 44 in the base portion. The open end portion of the cylinder 42 is threadedly secured to a cylindrical block member 46 that, in turn, has an axial bore 48 therethrough with an enlarged threaded portion 50. The end of the tubular connecting member 16 is threadedly secured in the enlarged bore 50 of actuator 14. Within the cylinder 42 there is positioned a piston 52 with a rod 54 extending therefrom through the bore 48 in the cylindrical block member 46. A spring 56 is positioned around the rod 54 and is arranged to urge the piston toward a retracted position as is illustrated in FIG. 1. Connected to opening 44 is a nipple 58 of a three-way sleeve valve 60. A spring 62 is provided to maintain the sleeve valve in a closed position. The other end of sleeve valve 60 is connected by a flexible conduit 64 to a suitable source of fluid under pressure. With this arrangement, movement of the sleeve valve 60 toward the actuator 14 compresses the spring 62 and opens the valve to supply fluid under pressure into the cylinder 42. Rearward movement of the sleeve will release the fluid pressure from within the cylinder and further rearward movement will maintain the sleeve valve 60 closed.

Within the tubular connecting member 16 there is provided a striking tool similar in many respects to the striking tool disclosed in US. Pat. No. 2,455,270. The striking tool 18 includes a tubular body portion 66 that is supported in spaced relation to the inner walls of the tubular connecting member by means of annular guides 68 and 70. The guides are suitably secured to the tubular body portion 66 and are movable therewith. A nut 72 is threadedly secured to the end of tubular body portion 66 adjacent the head member 12. The nut has an axial portion 74 through which a supporting member 76 extends into the inner portion of the striking tool body portion 66. The supporting member 76 has a threaded end portion 78 that is secured in the threaded bore 24 of head portion 12. With this arrangement the supporting member 76 remains fixed within the tubular connecting member 16 and the striking tool body portion 66 is arranged to move longitudinally over the surface of the supporting member 76.

The supporting member 76 has a plurality of spaced apertures 80 in the periphery thereof forming a circular ball cage in which balls 82 are positioned. An annular ring member 84 is positioned between the outer surface of supporting member 76 and the inner surface of tubular body portion 66. The annular ring has a plurality of ball receiving recesses 86 therein arranged to receive a portion of the balls 82 when the annular ring 84 is moved toward the head member 12 by the inner extending annular shoulder 88 of tubular body portion 66 abutting the annular end portion 90 of ring 84 and moving ring 84 toward the head portion 12. A return spring 92 is arranged to return the annular ring 84 to the position illustrated in FIG. 1 where a shoulder portion of ring 84 abuts the outwardly extending end shoulder 94 of supporting member 76.

A hammer 96 is positioned within the tubular body portion 66 and extends into the supporting member 76. The hammer has a striking end portion 98 and an annular recessed intermediate portion 100 in which the balls 82 extend to lock the hammer 96 in a rear or retracted position. The hammer 96 has an enlarged head portion 102 that abuts inturned shoulder portion 106 of the tubular body portion 66 and a striking spring 108 abuts the hammer enlarged head portion 102 and the rear wall 110 of tubular body portion 66. A return spring 112 is arranged to move the tubular body portion 66 to the position illustrated in FIG. 1. The spring 1 l2 abuts the outer turned shoulder 94 of supporting member 76 and the inturned shoulder 106 of tubular body portion 66. As the tubular body portion 66 moves toward the head member 12 the spring 112 is compressed and returns the body portion 66 to the position illustrated in FIG. 1.

The portable marking tool operates in the following manner. The sleeve valve 60 is moved forward against the spring 62 and admits fluid under pressure into the cylinder 42 to move the piston 52 and rod 54 axially as illustrated in FIG. 2 and compresses the spring 56. The rod 54 abuts the end portion 110 of the striking tool body portion 66 and moves the striking tool body portion 66 axially toward the head portion 12. The hammer 96 is locked in the position illustrated in FIG. 1 relative to the supporting member 76 and the balls 82 in ball cage 80 extend into the recessed portion 100 of hammer 96. The forward movement of the body portion 66 compresses the striking spring 108 and exerts a force against the enlarged head portion-102 of hammer 96. Further movement of the striking tool body portion 66 moves the body portion inturned shoulder 88 into contact with the end portion 90 of the annular ring member 84 and moves the ring member 84 therewith until the detent or recessed portions 86 are in underlying relation with the ball cage 80 of support member 76. When the recessed portions 86 of annular ring 84 are aligned the balls 82 move radially outwardly from the annular recessed portion 100 in the hammer 96 to release the hammer 96 from its retracted locked position. The hammer 96 is then propelled toward the head portion 12 and strikes the anvil 20 and transmits a marking force to the anvil 20. The parts are so dimensioned that the front face 114 of nut 72 abuts the inner shoulder 28 of head portion 12 as the hammer 96 is released from its rearward locked position as is illustrated in FIG. 2. It is believed that the abutting relation of the striking tool body portion 66 with the head portion 12 as the hammer 96 is released and propelled forward provides a structure that transmits the striking force of the hammer 96 through the anvil 20 and markers 36 to the object to be marked and has the desired velocity and force to impress a mark on the object without requiring the object to be positioned in a fixed support or having a mass sufficient to oppose the marking force of the anvil 20. With this arrangement it is now possible to mark objects by simply positioning the tool in abutting relation with the surface of the object to be marked and exerting little, if any, force on the marking tool to oppose the striking force of the portable marking tool.

It is also possible with the above described portable tion 12 includes a rearwardly extending slotted portion 116 having a plurality of slots 118 formed therein. The head portion 12 is slidably secured to the tubular connecting member 16 by means of the cap screws 120 positioned within the plurality of slots 1 18 and threadedly engaged to a cap member 122. The cap member 122 is threadably secured to the threaded end portion 78 of the supporting member 76 adjacent the head member 12. The cap has an axial bore 124 through which the supporting member 76 extends. A cap member shoulder portion 126 is retained in abutting contact with the end of the connecting member 16 and the slotted portion 116 by the cap screws 120 threadedly connected to member 16 and cap 122. With this arrangement, cap member 122 remains fixed within the marking tool 10 between the support member 76 and the connecting member 16. The set screw 128 threadably engages the head portion 12 to the chase 34 to provide for installation' and removal of the chase 34 in the forward end of the marking tool 10.

In the embodiment of the invention illustrated in the FIGS. 5 to 10, fluid under pressure is initially supplied to a fluid inlet conduit 130, which is suitably connected to a fluid reservoir (not shown). In the first embodiment of my invention described hereinabove, fluid under pressure is supplied directly from a reservoir through the conduit 64 to the sleeve valve 60; however, in the second embodiment of the invention the fluid under pressure is directed from the reservoir to the inlet conduit 130 before it enters the conduit 64 and sleeve valve 60.

The fluid inlet conduit 130 extends longitudinally above the marking device 10 and is threadably secured to one end of the inlet elbow joint 132 by nut 134. A nozzle 136 extending from the inlet elbow joint 132 other end is threadably secured within the head portion 12 and arranged in fluid communication with a transverse inlet passageway 137 in the head portion 12. The inlet passageway 137 intersects bore 138 within which a spool valve 140 is retained in the head portion 12 by the set screw 142.

The spool valve 140 is of conventional design,-as illustrated in FIG. 10, and includes a valve stem 144 connected at both ends to valve member 146 and valve member 148. The transverse inlet passageway 137 joins in fluid communication the inlet chamber 150 with the inlet conduit 130. The inlet chamber 150 extends rearwardly to meet the outletchamber 152, which also joins in fluid communication at the other end thereof with the exhaust chamber 154. The outletchamber 152 intersects the transverse outlet passageway 156 within the head portion 12. The outlet passageway 156 joins in fluid communicationthe chamber 152 with the outlet nozzle 158. The outlet nozzle 158 connects to an outlet elbow joint positioned in an outlet conduit (both not shown) for supplying fluid under pressure from the spool valve 140 to the cylinder 42 of the actuator 14 positioned in the rear portion of the marking tool 10. The outlet conduit is arranged in spaced parallel relation to the inlet conduit 130 and extends longitudinally above the surface of the marking tool 10.

A pin 160 projecting forwardly of the cap front face 164 is rigidly secured within the bore 162 adjacent the valve member 148. With this arrangement, .the head portion 12 moves rearwardly toward the cap front face 164 as the force exerted against the chase 34 is transmitted to the head portion 12. As the head portion 12 moves rearwardly, it contacts a plurality of pressure pins 166 arranged for longitudinal movement within bores 168 extending rearwardly from thefront face 164 to within the body of cap 122, as illustrated in FIGS. 6 and 7.

Referring to FIG. 7, the pin 166 extends from the front face 164 and abuts the spring 170 which is retained in the bore 168 between the pin 166 and the set screw 172. Thus, the rearward movement of the head portion 12 against the pressure pin 166 compresses the spring 170 and moves the pin 166 within bore 168 to provide for contact of thevalve member 148 with the pin 160. Contact of the valve member 148 with the pin 160 opens the valve 140 by displacing the shoulder portion 174 of valve member 146 from fluid tight engagement with the inlet chamber 150. The fluid under pressure contained within the inlet passageway 137 then enters the valve chamber 150 and passes therethrough to the outlet chamber 152. The outlet chamber 152 is sealed from the exhaust chamber 154 by the fluid tight engagement of the shoulder portion 175 of valve member 148. The fluid is then free to pass from the from the outlet chamber 152 through the outlet passageway 156 to the outlet conduit for supplying the fluid to the cylinder 42 in the rear of marking tool 10.

The spool valve member 148 must be moved forwardly so that the inlet chamber 150 is opened to permit passage of the fluid through the spool valve 140 to the chamber 42. Accordingly, the chase 34 must abut the object to be marked so that the head portion 12 is moved rearwardly to open the spool valve 140.

Without the chase 34 inserted in position within the head portion 12, the anvil 20 would be ejected from the support member 76 when the marking tool is actuated; therefore, the spool valve 140 is kept in closed position to prevent actuation of the tool 10 when the chase 34 is not in place within the head portion 12. The head portion 12 has a longitudinal bore 176 in which a pin 178 is positioned. When the chase 34 is in place within the head portion 12, as illustrated in FIG. 8, the chase 34 moves the pin 178 rearwardly to compress a spring 180 secured at one end to the pin 178 and at the other end within the conical bore 182 of the cap member 122. Rearward movement of the pin 178 also moves the peripheral recessed portion 184 of pin 178 from overlying relation with the arcuate tip of pin 186. Pin 186 has a laterally extending arm 188 thereon and is supported by a compression spring 190 secured to the screw 192 threadably engaged Within the bore 194. When the pin 186 is depressed by the cylindrical body portion of pin 178 the laterally extending arm 188 of pin 186 is below the shoulder 196 on the cap front face 164. When the arm 188 is positioned below the shoulder 196, the head portion 12 can be moved rearwardly to open the spool valve 140 and provide for the flow of fluid to the cylinder 42 of the actuator 14.

When the chase 34 is not in position within the head portion 12, as illustrated in FIG. 9, the pin 178 moves forwardly to permit the arcuate tip of pin 186 to move upwardly in the recessed portion 184. With this arrangement, the laterally extending arm 188 abuts the cap member face 164 thereby preventing rearward movement of the head portion 12 to open the spool valve 140 in the manner hereinabove described.

Referring to FIGS. 5, 8 and 9, there is illustrated a coil spring 198 arranged to return the tubular body portion 66 to the position illustrated in FIG. 1 for recocking of the marking tool 10. The spring 198 abuts at one end the annular nylon guide 200 within the recess 202 formed between the nut 72 and the connecting member 16 and at the other end the cap rear face 204. The annular nylon guide 200 is movable longitudinally with the tubular body portion 66 and is maintained in abutting relationship with the nut 72 threadably secured to tubular member 66. As the tubular body portion 66 moves toward the head member 12, the spring 198 is compressed. After actuation of the marking tool 10 thespring 198 urges tubular body portion 66 rearwardly to permit recocking of the marking tool 10.

The second embodiment of the invention, hereinabove described, assures actuation of the marking tool 10 only when the marker elements secured within the chase 34 are depressed against the object to be marked. Thus, the marking tool 10 will not discharge when the marking elements are not depressed against the object. In addition, the anvil 20 is prevented from being ejected as a projectile from the tubular body portion 66 when the chase 34 is not retained in place within the head portion 12. The engagement of pin 178 with pin 186 locks the head portion 12 in place to thereby block rearward movement thereof, which would otherwise open the spool valve 140 and actuate the marking tool 10. Even though the marking elements must be depressed against an object before the tool 10 is actuated, a substantial force is not required to be applied to the marking elements to move the head portion 12 rearwardly. As with the first embodiment, hereinabove described, only a relatively light force is required to be exerted on the marking tool 10 for actuation thereof.

The operation of the above described second embodiment of the portable marking tool to impress a mark of identification in the surface of an object, with the addition of the actuation features, is similar to the operation of the first embodiment. In the second embodiment, however, the front face 114 of the nut 72 abuts the rear face 204 of the cap member 122 as the hammer 96 is released from its rearward locked position. An annular ring 206 of resilient material retained in annulus 208 on the front face 114 of nut 72 surrounds in overlying relation the support member 72 and provides for absorption of shock forces applied to tubular body portion 66 upon impact of the nut 72 with the cap member 122. The abutting relation of the cap rear face 204 with the nut front face 114 and the cap from face 164 with inner shoulder 28 of the head portion 12, as the hammer 96 is released, transmits the striking force of the hammer 96 through the anvil 20 and the marking elements. Similarly, as with the first embodiment, the object to be marked is not required to be positioned in a fixed support as the striking force of the hammer 96 is transmitted to the markers in the second described embodiment of my invention.

It should be understood throughout the specification that the designation of the apparatus as a portable marking tool is intended to include any types of impressions applied to the surface of various objects and it is not intended to limit this apparatus to the use as an indicia marking tool.

According to the provisions of the patent statutes, I have explained the principle, preferred construction and mode of operation of my invention and have illustrated and described what I now consider to represent its best embodiments.

I claim:

1. A striking tool comprising,

a head member having a bore therethrough,

an anvil member movably positioned in said bore,

a hammer member arranged to move toward said anvil member and strike said anvil member with a marking force,

locking means to lock said hammer member in spaced relation to said anvil member,

propelling means to propel said hammer member toward said anvil member,

release means to release said locking means and permit said hammer member to be propelled by said propelling means toward said anvil member,

means for maintaining said head member in spaced relation to said propelling means so that said anvil member remains stationary within said head member,

an actuator to energize said propelling means, said actuator spaced from said head member with said hammer member therebetween, and

a connector member connecting said head member to said actuator so that said anvil member is operable to transfer said marking force from said hammer to a surface of an object to be marked.

2. A striking tool comprising,

a head member having a bore therethrough,

an anvil member movably positioned in said bore,

means retaining said anvil member in said bore,

a hammer member arranged to move toward said anvil member and strike said anvil member with a marking force,

locking means to lock said hammer member in spaced relation to said anvil member,

propelling means to propel said hammer member toward said anvil member,

release means to release said locking means and permit said hammer member to be propelled by said propelling means toward said anvil member,

, means for maintaining said head member in spaced relation to said propelling means so that said anvil member remains stationary within said head memher,

an actuator to energize said propelling means, said actuator spaced from said head member with said hammer member therebetween,

a valve means in said head member operable to actuate said actuator so that said propelling means moves longitudinally relative to said connector member and releases said locking means, and

said valve means arranged in fluid communication 4. A striking tool as set forth in claim 2 in which,

said valve means is operable to shut off the supply of fluid under pressure to said actuator when said head member is positioned in spaced relation from an object to be marked. 

1. A striking tool comprising, a head member having a bore therethrough, an anvil member movably positioned in said bore, a hammer member arranged to move toward said anvil member and strike said anvil member with a marking force, locking means to lock said hammer member in spaced relation to said anvil member, propelling means to propel said hammer member toward said anvil member, release means to release said locking means and permit said hammer member to be propelled by said propelling means toward said anvil member, means for maintaining said head member in spaced relation to said propelling means so that said anvil member remains stationary within said head member, an actuator to energize said propelling means, said actuator spaced from said head member with said hammer member therebetween, and a connector member connecting said head member to said actuator so that said anvil member is operable to transfer said marking force from said hammer to a surface of an object to be marked.
 2. A striking tool comprising, a head member having a bore therethrough, an anvil member movably positioned in said bore, means retaining said anvil member in said bore, a hammer member arranged to move toward said anvil member and strike said anvil member with a marking force, locking means to lock said hammer member in spaced relation to said anvil member, propelling means to propel said hammer member toward said anvil member, release means to release said locking means and permit said hammer member to be propelled by said propelling means toward said anvil member, means for maintaining said head member in spaced relation to said propelling means so that said anvil member remains stationary within said head member, an actuator to energize said propelling means, said actuator spaced from said head member with said hammer member therebetween, a valve means in said head member operable to actuate said actuator so that said propelling means moves longitudinally relative to said connector member and releases said locking means, and said valve means arranged in fluid communication with said actuator.
 3. A striking tool as set forth in claim 2 in which, said head member includes a rear wall, said propelling means includes a tubular body portion with a front end portion, said head member operable to move toward said tubular body portion upon contact with an object to be marked so that said head member rear wall moves into abutting relation with said tubular body front end portion whereby said valve means operably supplies fluid under pressure to said actuator.
 4. A striking tool as set forth in claim 2 in which, said valve means is operable to shut off the supply of fluid under pressure to said actuator when said head member is positioned in spaced relation from an object to be marked. 